Some radio transmitters radiate a radio data signal (RDS) that may contain a variety of informational content such as traffic information. Another form of informational signal that may be integrated in a radio transmission is known as Autofahrer Rundfunk Information (ARI). Also, in some locations a radio transmission may include both an RDS component and an ARI component. Both the RDS and the RI signals are radiated with a carrier signal specified by the Cenelec EN50067:1998 standard to be 57 kHz. For RDS signals, the carrier is suppressed. A receiver, thus, may receive a multiplex signal from one transmitter or, depending on its physical location, a mix of RDS and ARI signals, or only RDS, or only ARI signals. The receiver, thus, must be capable of recognizing the three possibilities, and distinguish between the three signals, whether they occur separately or simultaneously.